Begging it is used when:
1. someone is trying to suck up to someone for example, laughing at a joke that really isnt funny.
2. Someone asks for money to go and buy someone or asks for someones food
3. Someone who spends time around someone and really fancies them and is completely undignifies about it.

1. "Stop begging it off your mum."
2. "Stop begging it off him for cash you trampy whore, leave him alone and get your own you tramp."
3. "Allow begging it off him, you blatently fancy him"